Centrifugal pressure nozzle

ABSTRACT

An improved centrifugal pressure nozzle for spraying the highly viscous fluid in a uniformly atomized state. The spray nozzle has a swirl chamber constituted by a cylindrical hollow portion contiguous to a frusto-conical hollow portion communicated with a fluid outlet or orifice. The ratio A/A&#39;&#39; of the total sectional area A of the fluid inlets to the swirl chamber to the sectional area A&#39;&#39; of the cylindrical hollow portion of the swirl chamber is selected to be 0.5 to 1.0 so that the frictional resistance offered by the inner surface wall of the spray nozzle may be minimized for realizing a stable spray pattern and a uniform particle size of the atomized fluid.

United States Patent Nakamura et al. June 3, 1975 [54] CENTRIFUGAL PRESSURE NOZZLE 3,013,731 12/1961 Carlisle 239/468 X 3,304,013 2 1967 0'}! 239 468 [75] Inventors: Masayoshi Nakamura, Koshigaya; I men I Tadayoshi Tamura Yachiyo; Sadao FOREIGN PATENTS OR APPLICATIONS y u s all of Japan 815,104 6/1959 United Kingdom 239/463 [73] Assignee: Lion Fat & Oil Co., Ltd., Tokyo,

Japan Primary ExammerRobert S. Ward, Jr.

Attorney, Agent, or Firm-Woodhams, Blanchard & [22] Filed: Apr. 8, 1974 Hymn [2l] Appl. No.: 458,768

[57] ABSTRACT [30] Foreign Application Priority Dam An improved centrifugal pressure nozzle for spraying A 13 I973 Ja an 4804379] the highly VISCOUS fluid in a uniformly atomized state. p The spray nozzle has a swirl chamber constituted by a cylindrical hollow portion contiguous to a frusto- [52] US. Cl. 239/468, 239/504, 2255/2056, conical hollow portion communicated with a fluid out 51 I t Cl Bosh let or orifice. The ratio A/A of the total sectional area i 504 505 A of the fluid inlets to the swirl chamber to the secl 0 2319/51 6 tional area A of the cylindrical hollow portion of the swirl chamber is selected to be 0.5 to 1.0 so that the 56 R f d frictional resistance ofiered by the inner surface wall I e erences of the spray nozzle may be minimized for realizing 21 UNITED STATES PATENTS stable spray pattern and a uniform particle size of the 2,2l8,l 10 10/1940 Hosmer et al. 239/468 X atomized fluid, 2,557,247 6/195l Ziherl 239/468 X 2,666,669 1 1954 Wahlin 239/468 5 Clams, 4 Drawing Flgllres PATHUE LHM 1975 FIG. 2

FIG. I

CENTRIFUGAL PRESSURE NOZZLE BACKGROUND OF THE INVENTION a. Field of the invention This invention relates to an improved centrifugal pressure nozzle having a hollow inside space and a frus to-conical orifice element and adapted for spraying the highly viscous fluid in a uniformly atomized state and with a constant hollow cone spray pattern.

b. Description of the prior art The conventional centrifugal pressure nozzle used for spraying the highly viscous fluid and provided with a hollow inside space andd a conical orifice element had only one or two fluid inlets to the swirl chamber and the ratio A/A of the total sectional area of the fluid inlets to the sectional area A of the swirl chamber amounting to 0.05 to 0.25. With such a spray nozzle, since the fluid had to be sprayed under a considerably elevated pressure, the fluid encountered an increased frictional resistance offered by the inner wall surface of the spray nozzle and was necessarily disturbed in flow so that the particle sizes of the atomized fluid were fluctuated in a rather wide range and the spray pattern was also disturbed. Moreover, the spray angle was not maintained constant on account of fluctuations in the discharge coefficient of the fluid from orifice.

SUMMARY OF THE INVENTION An object of this invention is to provide a spray nozzle for spraying the highly viscous fluid in a uniformly atomized state and with a constant spray pattern.

Another object of the invention is to provide a spray nozzle for spraying the highly viscous fluid with the minimum fluctuations in the spray angle and under stabilized spraying conditions.

A further object of the invention is to provide a spray nozzle for spraying the highly viscous fluid at a lower pressure than that used in the conventional spray nozzle.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a central longitudinal section showing a first embodiment of the spray nozzle according to the present invention;

FIG. 2 is a transverse section of the core element used in the embodiment of FIG. 1;

FIG. 3 is an elevation showing the core and orifice elements used in the embodiment of FIG. I; and

FIG. 4 is a central longitudinal section showing a modified embodiment of the spray nozzle according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION FIG. I shows in a central longitudinal view a first embodiment of the spray nozzle of the present invention.

In FIG. 1, the numeral 1 denotes one of the inlets of the viscous fluid into a swirl chamber 2. Preferably, each inlet 1 is opened into the swirl chamber 2 tangentially at one side thereof which corresponds to the right-hand side or left-hand side of the inlet 1 as seen in the flow direction of the fluid in the sectional view of FIG. 2. In addition, the inlets 1 are disposed equiangularly around the rim of the vortex chamber 2. For instance, when the spray nozzle has three inlets l to the vortex chamber 2, as shown in FIG. 2, the sides of the inlets 1 that run tangentially to the swirl chamber 2 should intersect each other at an angle of 60 and,

Lil

when the nozzle has four inlets 1, the sides as defined above should intersect each other at a right angle. Such an arrangement of the inlets 1 relative to the swirl chamber 2 facilitates the viscous fluid to flow in a swirl through the swirl chamber 2 towards an outlet orifice 8. According to this invention, several and preferably three to six inlets are provided in the above disposition. The sectional shape of each inlet 1 may be polygonal and preferably quadrilateral. but it may also be circular as the occasion may demand.

The swirl chamber 2 is constituted by a frustoconical hollow portion and a cylindrical hollow portion contiguous thereto and provided at its upper rim with the above-mentioned fluid inlets 1. According to one aspect of the present invention, the ratio A/A' of the total sectional area A of the vortex chamber inlets l to the sectional area A of the cylindrical hollow portion of the swirl chamber 2 is selected to be within the range of 0.5 to L0.

In case A/A is 0.5 or less, as highly viscous fluid is required to be sprayed at high pressure, the friction inside the nozzle comes to increase, resulting in that the spray angle is narrowed and the discharge coefficient becomes larger.

Under such a situation, the spray pattern is disturbed in shape, and the particle sizes of the atomized fluid tend to become nonuniform. On the other hand, when the ratio A/A' as defined above is larger than 1.0, the swirling action of the highly viscous fluid in the swirl chamber 2 is affected adversely and thus the resulting spray pattern becomes unstable and deviates from the desired hollow conical shape.

The fluid passage from the swirl chamber inlets l to the outlet orifice 8 is constituted by an orifice element 3 and a core element 4. The core element 4 shown in FIG. 3 is formed with the upper half portion of the vor tex chamber, and the core element 4 in the embodiment of FIG. 4 is solid and the inlets l as well as the swirl chamber 2 are formed in the orifice element 3. The core element 3 and the holder 5 constitute an annular passage for the viscous fluid that is communicated with the spray orifice 8 through the fluid inlets l. The core element 4 and the orifice element 3 are secured in position in a holder 5 by a coil spring 6 retained at its upper end by an upper nozzle element screwed to the holder 5 and resting at its lower end on the upper surface of the core element 4. The upper nozzle element has a threaded inlet 7 to which is screwed a fluid passage, not shown, that is connected to a fluid source, also not shown, that is designed to supply the fluid under an elevated pressure to the spray nozzle.

In the above consturction of the spray nozzle, the highly viscous fluid supplied from the inlet 7 of the upper element flows through a cylindrical hollow portion for mounting the spring and a frusto-conical hollow portion contiguous to the cylindrical hollow portion. The fluid then flows through several fluid inlets I provided to the core element 4 or to the orifice element 3 into the swirl chamber 2 where it is subjected to a swirlin g action. The fluid is sprayed in a constant spray pattern from the spray orifice 8.

According to the present invention, when spraying the highly viscous fluid having a viscosity in the order of 200 poises, the fluid can be sprayed at a pressure of 5 kg/cm, in contrast to the pressure of about 10 kglcm required in case of using the conventional spray nozzle.

Since the fluid can be sprayed in this way at a rather low pressure, the frictional resistance offered by the inner surface wall of the spray nozzle may be reduced, thus resulting in the undisturbed flow of the viscous fluid through the spray nozzle and the constant particle size of the atomized fluid.

In case of spraying the liquid variable in viscosity by the use of conventional nozzles the spray angle and discharge coefficient vary as its viscosity varies, thereby making impossible obtainment of uniform spray pattern. Contrary to this, when using the nozzle of the present invention the spray angle and discharge coefficient are stable in spite of variation in viscosity, thereby permitting obtainment of uniform spray pattern and also stabilizing the spray conditions.

It is evident from aforesaid results, that the use of the nozzle of the present invention for spray-drying detergent slurry, which is highly viscous and highly variable in viscosity, makes it possible to obtain uniform spray pattern, and stabilizes the conditions within the drying tower, thereby promoting the constant detergent particle of the atomized fluid.

What is claimed is:

l. A spray nozzle having a swirl chamber constituted by a cylindrical hollow portion contiguous to a frustoconical hollow portion, characterized in that several fluid inlets are provided so as to open in the swirl chamher, and the ratio A/A' of the total sectional area A of the fluid inlets l to the sectional area A of the cylindrical hollow portion of the swirl chamber 2 is in the range of 0.5 to 1.0.

2. A spray nozzle as claimed in claim I wherein three to six fluid inlets l are provided so as to open into the swirl chamber.

3. "lhe spray nozzle as claimed in claim I wherein each inlet 1 is opened into the swirl chamber 2 tangentially at one side thereof which corresponds to the right-hand side or left-hand side of the inlet as seen in the flow direction of the fluid.

4. The spray nozzle as claimed in claim 1 wherein the core element 4 is formed with the upper half of the swirl chamber 2 and the fluid inlets l and the orifice element 3 is formed with the lower half of the swirl chamber 2.

5. The spray nozzle as claimed in claim 1 wherein the core element 4 is solid and the orifice element 3 is formed with the fluid inlets 1 and the swirl chamber 2. =8 

1. A spray nozzle having a swirl chamber constituted by a cylindrical hollow portion contiguous to a frusto-conical hollow portion, characterized in that several fluid inlets are provided so as to open in the swirl chamber, and the ratio A/A'' of the total sectional area A of the fluid inlets 1 to the sectional area A'' of the cylindrical hollow portion of the swirl chamber 2 is in the range of 0.5 to 1.0.
 1. A spray nozzle having a swirl chamber constituted by a cylindrical hollow portion contiguous to a frusto-conical hollow portion, characterized in that several fluid inlets are provided so as to open in the swirl chamber, and the ratio A/A'' of the total sectional area A of the fluid inlets 1 to the sectional area A'' of the cylindrical hollow portion of the swirl chamber 2 is in the range of 0.5 to 1.0.
 2. A spray nozzle as claimed in claim 1 wherein three to six fluid inlets 1 are provided so as to open into the swirl chamber.
 3. The spray nozzle as claimed in claim 1 wherein each inlet 1 is opened into the swirl chamber 2 tangentially at one side thereof which corresponds to the right-hand side or left-hand side of the inlet as seen in the flow direction of the fluid.
 4. The spray nozzle as claimed in claim 1 wherein the core element 4 is formed with the upper half of the swirl chamber 2 and the fluid inlets 1 and the orifice element 3 is formed with the lower half of the swirl chamber
 2. 